Why does group 2 on the periodic chart go down in density and then goes up in density while the radius is always getting larger.

What is the most likely chemical explanation for the fact that butter is a solid at room temperature while olive oil is a liquid? Answer a. Butter is an animal fat while olive oil is a vegetable fat. b. Butter is high in monounsaturated fats. c. Butter is a fat while olive oil is an oil. d. Butter is much higher in saturated fat than olive oil.